Alternating Current Potential Drop Probe Alternating current potential drop (ACPD) testing is a...
-
Upload
percival-preston -
Category
Documents
-
view
215 -
download
0
Transcript of Alternating Current Potential Drop Probe Alternating current potential drop (ACPD) testing is a...
Alternating Current Potential Drop ProbeAlternating Current Potential Drop Probe
Alternating current potential drop (ACPD) testing is a relative newcomer to the area of nondestructive evaluation (NDE). Developed in the 1980’s, ACPD testing currently uses two point probes for single frequency (typically 5kHz) measurements of crack depths, crack growth, and material properties. Although this type of testing is effective, there are several limitations, including the need to perform the tests over a wide range of frequencies. To counter these problems, the intent of this project will be to design four four-point ACPD probes. Two probes will be used for lower frequencies (1 Hz to 10 kHz) and the others for higher frequencies (100 kHz to 10MHz). As a result of producing these probes, it will be easier for users to test materials more efficiently, accurately, and effectively.
Abstract
Project Team InformationDESIGN TEAM MAY05-17
Jacob Chatterton (EE)
Jennifer Johnson (EE)
Jonathan O’Dell (EE)
Jordan Vos (EE)
FACULTY ADVISORS
Dr. John Bowler
Dr. Nicola Bowler
CLIENT:
Center for Nondestructive Evaluation1915 Scholl Road
111 ASC IIAmes, Iowa 50011-3042
Project RequirementsDesign Objectives•Build the in-line and square head probes for each frequency range
Functional Requirements Ability to work over a wide range of frequencies
Capability to control the effect of the inductive pick-up
Easy to maintain and service as needed
Design Constraints Must be handheld and portable
Voltage pin connections must be durable and long-lasting
Construction of four prototype probes (December 2004)
Performance testing of prototypes (January 2005)
Finish user’s manual and technical report (April 2005)
Approach and Considerations
Proposed Approach Analyze commercially available probes
Build and test prototype probes in lab and compare with theory
Revise probe design until satisfactory
Technologies Considered Square Head Design
In-Line Design
Testing Considerations Compare laboratory tests to theory to check accuracy
Provide and reference voltage to the injected current
Provide effective control or regulation of the inductive pick-up
Estimated Resources and Schedule
Problem StatementDevelop four probes that can be used for two bands of frequencies as well as different alignments.
Solution Approach Research ACPD theory and probe technologies currently used in the field
Perform laboratory tests on all design prototypes
Investigate the material properties of different types of steels
Intended Uses and Users Assessment of steel vehicle shafts and case-hardened components
Observation/characterization of cracks and defects in aircraft engine disks
Probe will be operated by trained technicians
Operating Environment Probes will be used in a laboratory testing setting
Probes will also be used in production line environment
End Product and Other Deliverables Four probes: two for each frequency range with two different head designs (square and in-line)
User’s manual with usage, calibration, and repair instructions
Assumptions The developed theory will be accurate
Probe materials and machining will be available
Laboratory testing time and equipment will be available
Limitations• Probes built for two different frequency ranges
• Low frequency: 1 Hz to 10 kHz
• High frequency: 100 kHz 10MHz
• Voltage pin connections must be made close to test surface
• Probes must be robust and portable
Introduction
Closing Summary
Alternating current potential drop (ACPD) measurement and testing within the area of nondestructive evaluation (NDE) is a rapidly growing field. Currently, the probes used in the field are limited by their size and operating frequencies. By the end of this project, the team will have created four hand-held probes, which will be capable of taking measurements over a vast range of frequencies. These new probes will aid in the advancement of ACPD testing within the area of NDE.
Member Name HoursJennifer Johnson 164Jacob Chatterton 165Jonathan O'Dell 161
Jordan Vos 163
Milestones
Project Schedule Personnel Effort Financial Resources
5 12 19 26 3 10 17 24 31 7 14 21 28 5 12 19 26 2 9 16 23 30 6 13 20 27 6 13 20 27 3 10 17Project TasksProject DefinitionTechnology Considerations & SelectionEnd Product DesignEnd Product Prototype ImplementationEnd Product TestingEnd Product DocumentationEnd Product Demonstration
Summary Milestone
January February March AprilSeptember October November DecemberProbe
examples, $100, 14%
Miscellaneous, $100, 14%Spring
Contacts, $100, 14%
Probe Machining, $300, 44%
Probe materials,
$100, 14%